Video technology realizes a remote transmission that integrates information such as voice, images and data, so that peoples who are remotely communicating with each other using the video technology can not only hear voice of the other party, but also see moving images and film contents thereof, thus the communication becomes far more cordial and telepresent.
A video conference system consists of a Multipoint Control Unit (MCU) and terminals. Each terminal corresponds to a venue, collects and encodes sounds and images of the venue, and transmits the sounds and images to the MCU. The MCU processes the sounds and images in a certain manner, such as sound mixing, image forwarding or multi-picture formation, and transmits the processed sounds and images to respective terminals. The terminals decode and output the sounds and images from the far-end venues, thereby realizing a remote communication.
There are mainly two methods for switching video pictures in a cur rent video conference.
The first method is one of requesting via a remote controller. When a participant in Venue 1 wants to watch a picture of Venue 2, he/she shall send conference control information through the remote controller, and request to the MCU for watching a picture of Venue 2. Upon receiving the control information “Venue 1 request watching a picture of Venue 2” sent from the terminal of Venue 1, the MCU forwards the video stream of Venue 2 to Venue 1. As a result, Venue 1 performs the picture switching function one time.
The second method is a voice exciting image (also referred to as voice activated switch) method, which determines a venue at which the current speaker is located by comparing the volumes of the voices at respective venues in the conference, and automatically broadcasts the picture of the venue to other venues for watching.
During the implementation of the present invention, the inventors find that the existing technology at least has the following problem:
The method of requesting via a remote controller frequently switches pictures through the remote controller, which affects continuity and interactivity of the conference. The method of voice activated switch broadcasts a picture of a venue to other venues for watching only when a speech is made in the venue, thereby causing a certain hysteresis.